Stacking device

ABSTRACT

A stacking device is described for stacking articles diverted from a first conveyor in a predetermined location into a parallel stacking position. The device includes a second conveyor mounted between the predetermined location and the input of the stacking position. The second conveyor is pivoted about its input and near the predetermined location, such that the second conveyor is angularly displaced as a function of the thickness of a stack of articles accumulated in the stacking position. The effective path length of the second conveyor is also varied as a function of the angle it makes with the first conveyor.

United States Patent STACKING DEVICE 1 14 Claims, 2 Drawing Figs.

US. Cl. Int. Cl

Relerenees Cited UNITED STATES PATENTS 2,660,432 1 1/1953 Wilske et al.

I651! 29/14 Field of Search 271/68, 69,

1,305,501 6/1919 Steele 271/68 3,321,202 5/1967 Martin 271/68 3,152,701 10/1964 Weiland 271/68 X ABSTRACT: A stacking device is described for stacking articles diverted from a first conveyor in a predetermined location into a parallel stacking position. The device includes a second conveyor mounted between the predetermined location and the input of the stacking position. The second conveyor is pivoted about its input and near the predetermined location, such that the second conveyor is angularly displaced as a function of the thickness of a stack of articles accumulated in the stacking position. The effective path length of the second conveyor is also varied as a function of the angle it makes with the first conveyor.

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STACKING DEVICE STACKING DEVICE The present invention relates to a stacking device for stacking articles diverted from a conveyor in a predetermined location into a stacking position.

Such a stacking device may for instance be associated with each of a plurality of operators positions at a coding desk of a mail-handling machine, wherein documents fed to this operators position via a common conveyor and entrance mechanism must be stacked in a stacking position in such a manner that the documents of the stack are substantially parallel to the conveyor.

It is an object of the present invention to provide a stacking device which is particularly adapted to stack these documents in a relatively thick stack and in such a manner that the documents being stacked are suitably guided during their displacement from said entrance mechanism to said stacking position.

The stacking device according to the present invention is particularly characterized in that it includes a second conveyor mounted between said predetermined location and the input of said stacking position, said second conveyor being pivoted about its input end near said predetermined location, and that said second conveyor is angularly displaced in function of the varying thickness of the stack of articles accumulated in aid stacking position, the length of said second conveyor being varied in function of the angle it makes with said first conveyor. v

The present device is also characterized in that it further includes a second conveyor mounted between said predetermined location and the input of said stacking position, said conveyor being pivoted about its input end near said predetermined location and being constituted by a first conveyor part and by a second conveyor part, that said second conveyor is angularly displaced in function of the varying thickness of the stack of articles accumulated in said stacking position, and that means are provided to continuously urge said first and second conveyor parts into contact with each other.

The above-mentioned and other objects and features of the invention will become more apparent and the invention itself will be best understood by referring to the following description of an embodiment taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a plan view of the stacking device of the present invention in a characteristic position;

H6. 2 is a view similar to FIG. 1 but with the stacking device in another characteristic position.

Referring to these drawings the stacking device 1 shown therein forms part of a coding desk of a mail-handling machine which further includes a conveyor belt schematically represented by reference numeral 2, an entrance member 3 which is fixed in an axle 4 which may be angularly displaced by an entrance mechanism (not shown) from a rest position (FIG. 2) into an operative position (FIG. 1) and vice versa; and an operators position including a conveyor belt schematically represented by reference numeral 5.

Stacking device 1 is adapted to stack documents such as 6 in a stacking position 7 which is delimited by side frame 8 and by conveyor belt 5. A base plate 9 mounted in this stacking position 7 is displaceable in the direction of arrows 10 and carries a flat guide member 11 near its side facing conveyor belt 2 and an upstanding guide plate 12, 13 near its side facing conveyor belt 5. Portion 12 of this guide plate makes an angle of about 45 with the plane of conveyor belts 2 and 5, while portion 13 of this member is parallel to these belts. Base plate 9 is coupled to drive means (not shown) which are controlled by detecting means (also not shown) of the thickness of the stack of documents accumulated in the stacking position and which displace base plate 9 towards or away from conveyor belt 5 when this thickness decreases or increases respectively. Portion 13 of the guide plate 12, 13 hereby maintains the documents of the stack in their upright position by pressing them towards conveyor belt 5. Base plate 9 is further provided with a pivot axle 14 on which idler 15 is mounted. This idler 15 is located adjacent the input end of guide plate portion 12. A cam-shaped lever 16 is hingedly connected to axle 14 and has a pivot axle 17 on which idler 18 is mounted. Spring 19 continuously tends to pivot cam-shaped lever 16 and idler 18 in clockwise direction. Finally, base plate 9 carries two coaxial integral idlers 20, 21 which are mounted on axle 22, the outer idler 21 being provided with peripheral elastic inserts such as 2 A conveyor generally indicated by reference numeral 57 is mounted between entrance point member 3 and stacking position 7. it includes a bracket 24 which is free to turn about pivot axle 25 and which carries idlers 26, 27 and 28 mounted on the respective axles 25, 29 and 30. A conveyor belt 31 is arranged around idlers 26, 27 and 28 which is integral with idler 32. The latter idler 32 is connected to idler 20 by means of elastic belt 33 which continuously tends to turn idlers 28, 32 and hence conveyor belt 31 in clockwise direction. ldler 26 is connected by drive belt 34 to roller 35 which is fixedly mounted on drive shaft 36 coupled to other driving means (not shown). it should be noted that the lower face of idler 28 is located at a certain distance from base plate 9 so that its axle 30 may follow guide member 11.

The above conveyor 57 further includes a bracket 37 which is free to turn about pivot axle 38 and which continuously tends to pivot in counterclockwise direction due to the presence of spring 39 attached between pins 40 and 41. Bracket 37 carries axles 42 to 45 on which idlers 46 to 49 are mounted and at its end adjacent lever 16 it is further provided with an arm 50 carrying idler 51. The above conveyor 57 further includes an idler 52 which is mounted at the end of lever 53 which is free to turn about axle 54, this idler 52 continuously tending to pivot in counterclockwise direction due to the presence of spring 55. Finally a small plate 56 is mounted adjacent entrance point member 3 and determines with the latter the entrance of the stacking device 1.

From the above it follows that a good contact is continuously ensured between conveyor belt 31 and idlers 52, 46 to 49 and 18 since springs 55, 29, 19, on the one hand, and elastic belt 33, on the other hand, tend to turn conveyor belt 31 in opposite directions. As will become clear later also a good contact is realized between conveyor belt 31 and idler 15 due to the presence of elastic belt 33 and guide member 11. In this connection it should be noted that since idler 15 delimits with guide plate portion 12 and conveyor belt 31 the input of the stacking position 7 it must have a fixed position with respect to this plate portion and hence cannot be mounted in the same way as idlers 52, 46 to 49 and 18 which are able to pivot.

The operation of stacking device 1 is as follows.

The above-mentioned driving means associated to drive shaft 36 being operated conveyor belt 31 is driven through the intermediary of driver roller 35, drive belt 34 and idler 26. This conveyor belt 31 hereby drives idlers 52, 46 to 49, 18 and 15 since they make contact with this belt 31. The latter belt in its turn drives idler 21 having peripheral elastic inserts 23 via idler 32, elastic belt 33 and idler 20.

It is assumed that the stacking device 1 is in the position shown in FIG. 1 except for entrance point member 3 which is first assumed to be in the rest position shown in FIG. 2. The thickness of the stack of documents such as 6 accumulated in stacking position 7 is shown to be nearly a minimum. This stack is pressed against conveyor belt 5 by guide plate portion 13 and against side frame 8 by the force exerted in the direction of this frame by the rotating elastic inserts 23 of idler 21.

The documents of the accumulated stack are successively processed by an operator and each time a document 6 leaves stacking position 7 by being shifted by conveyor 'belt 5 towards the operators position, displaceable base plate 9 is gradually advanced towards the latter conveyor belt 5 to maintain the remaining stack under pressure. Hereby conveyor 57 is gradually angularly displaced.

At the moment the thickness of this stack of documents reaches a predetermined minimum value the above-mew tioned detecting means operate the above entrance mechanism due to which entrance point member 3 is brought in the position shown in FIG. 1. Hereby it should be noted that the angle between elastic belt 33 and side frame 8 then reaches a relatively large value. Simultaneously with the operation of entrance point member 3 a document feed mechanism (not shown) is operated in the coding desk so that a stream of shingled documents, i.e. having overlapping edge positions, is fed to stacking device 1 via conveyor belt 2. When these documents arrive at the stacking device 1 they are diverted by entrance point member 3 into the entrance of this device and transferred via plate 56, conveyor 57 and guide plate 12, 13 into stacking position 7 where a relatively thick stack is thus gradually formed. During their displacement by conveyor 57 these documents are advanced between conveyor belt 31, on the open hand, and successively idlers 52, 46, i7, 48, 49, 18 and 15 on the other hand. At the moment the Reading edges of these documents leave portion 12 of guide plate 12, 13 and arrive on portion 13 thereof these documents undergo a sudden change of direction due to which the rear portions of these documents tend to turn in counterclockwise direction and do so when these rear portions leave conveyor 57. Moreover, the elastic inserts 23 urge these documents towards side frame 8 by which they are stopped.

As the thickness of the stack of documents being formed in stacking position 7 gradually increases base plate 9 is gradually displaced in a direction away from conveyor belt so that the angle between elastic belt 33 and side frame 8 gradually decreases.

It should be noted that as long as the last-mentioned angle is relatively large the force exerted on conveyor 31 by elastic belt 33 to turn it in clockwise direction is relatively small. Notwithstanding this disadvantageous position of elastic belt 33 the documents to be stacked are correctly advanced between conveyor belt 31 and idlers 52, 46 to 49, and 18 due to the presence of the springs 55, 39 and 19 respectively. Although no spring is associated to idler these documents are also correctly advanced between idler 15 and conveyor belt 31 due to the presence of guide member 11 which is followed by axle 30 of idler 28 of belt 31. The shape of this guide member 11 is indeed such that when it is followed by this axle 30 during the displacement of base plate 9 the distance between axle 14 of idler 15 and adjacent conveyor belt 31 substantially remains constant although the latter idler 15 and belt 31 follow a rectilinear path and a circular path respectively. A good driving of the documents between idler 18 and conveyor belt 31 is required in order to ensure as long as possible a positive guiding of these documents before they are liberated against guide plate 12, 13.

During the above displacement of displaceable plate 9 camshaped lever 16 mounted thereon follows a rectilinear path, while idler 51 follows a circular path and hereby approaches cam-shaped lever 16. ln a predetermined relative position of displaceable plate 9 and idler 51 the latter comes into contact with the edge of lever 16 facing conveyor belt 2. During the further movement of the displaceable plate 9 and idler 51 the latter pivots lever 16 in anticlockwise direction due to which idler 18 is brought out of engagement with conveyor belt 31. In other words the path length of the conveyor part constituted by idlers 52, 46 to 49, 18, 15 of conveyor 57 is decreased when the thickness of the stack of documents accumulated in stacking position 7 is increased i.e. when the angle between conveyors 2 and 57 is decreased.

It should be noted that during the time interval documents are stacked in the stacking position documents are processed by the operator. But as the stacking operation of a document is performed at a much higher speed than the processing of a document the thickness of the stack of documents accumulated in the stacking position increases during the stacking operation.

When the thickness of this stack reaches a maximum value this is detected by the detecting means which stop the movement of base plate 9 and which operate the above-mentioned entrance mechanism. Due to this, entrance point member 3 is pivoted into its inoperative position shown in FIG. 2. The other constituent elements of stacking device 1 are in the position shown in this figure.

The thickness of the stack of documents then again gradually decreases due to the fact that these documents are successively processed by the operator. It is clear that base plate 9 is then again gradually displaced towards the conveyor belt 5. Consequently the distance between idler 51 and lever 16 is gradually increased so that the latter is gradually angularly displaced in clockwise direction hereby bringing at a certain moment idler 18 in contact with conveyor belt 31. In other words the path length of conveyor part constituted by idlers 52, 46 to 49, 18, 15 of conveyor 57 is increased when the thickness of the stack of documents accumulated in stacking position 7 is decreased, i.e. when the angle between conveyors 2 and 57 is increased.

While guide member 11 is necessary as long as the angle between elastic belt 33 and side plate 7 is relatively large it becomes quite unnecessary when this angle becomes very small as is the case when base plate 2 approaches conveyor belt 2. Indeed the force exerted by elastic belt 33 is then relatively high.

From the above it follows that conveyor 57 which is angularly displaced in function of the varying thickness of the stack of documents accumulated in stacking position 7 is constituted by a first conveyor part of constant length constituted by conveyor belt 31 and by a second conveyor part of variable length, the latter second conveyor part being itself constituted by a conveyor part of constant length including idlers 52 and 46 to d9 and by a conveyor part. of variable length 15, 18.

It should be noted that in the above-described operation of the stacking device 1 new documents are accumulated in the stacking position each time the thickness of the stack reaches a predetermined minimum value. But it is clear that at the end of a day for instance all the documents of a stack will be processed without new documents being transferred to the stacking position.

As described above the documents to be stacked have overlapping edges. This enables the stacking device to stack a large number of documents per time unit, there being no danger that the leading edge of a document will abut against the trailing edge of a preceding document. In case the documents do not have overlapping edges the number of documents which may be stacked per time unit is smaller since the distance between each pair of successive documents must be such that the trailing edge of the first document of the pair arriving in the stacking position is deflected out of the path followed by the leading edge of the second document before that document arrives in this stacking position.

While the principles of the invention have been described above in connection with specific apparatus, it is to be clearly understood that this description made only by way of example and not as a limitation on the scope of the invention.

lclaim:

1. Stacking device for stacking articles diverted from a first conveyor (2) in a predetermined location into a parallel stacking position (7) comprising:

a second conveyor (57) mounted between said predetermined location and the input of said stacking position, said second conveyor being pivoted about its input and near said predetermined location, and said second conveyor is angularly displaced as function of the varying thickness of a stack of articles (6) accumulated in said stacking position, such that the effective path length of said second conveyor is varied as a function of the angle it makes with said first conveyor (2);,

a displaceable plate (99) mounted in said stacking position and displaceable as a function of the thickness of said stack;

said second conveyor includes a first conveyor means (31) the angular displacement of which is controlled by said displaceable plate, and a second conveyor means (52, 46-49, 18, cooperating with said first means to form the variable effective path length of said second conveyor; and

means (55, 39, 19, 33) to urge said first and second conveyor means into contact with each other,

whereby said articles are conveyed between said first and second means forming the variable effective path length.

2. Device according to claim 1, wherein said second conveyor means comprises a constant portion (52, 46-49), and a variable portion (18, 15) including a first idler (18) which is mounted on a first lever (16) pivoted on said displaceable plate (9) near the impact of said stacking position (7), the position of said first idler is controlled by said constant portion so that said first idler makes contact with said first conveyor means depending on the angular position of said constant portion.

3. Device according to claim 2, wherein said variable portion further includes a second idler (15) mounted on the pivot axle (14) of said first lever (16) and forms, together with the adjacent portion of said first conveyor means, the input of said stacking position.

4. Device according to claim 3 wherein said first lever (16) comprises a first cam-shaped member, the position of which is controlled by a third idler (51') mounted on said constant portion near the output end thereof.

5. Device according to claim 4, wherein said first conveyor means (31) comprises an endless belt arranged on fourth idlers (26-38), and said constant portion of said second conveyor means comprises a plurality of juxtaposed fifth idlers (46-49) mounted on a second lever (37) which is pivoted (38) near said predetermined location.

6. Stacking device according to claim 1, wherein said urging means includes an elastic member (33) one end of which is connected to the output end (32) of said second conveyor means (31) and the other end of which is connected to said displaceable plate (9).

7. Stacking device according to claim 6 wherein said other end of said elastic member is connected to said displaceable plate at a location away from the input of said stacking position and near the side of said displaceable plate opposite to that facing said first conveyor (2).

8. Stacking device according to claim 7, wherein said elastic member (33) comprises an elastic belt which is arranged around a sixth (32) and a seventh idler, said sixth idler (32 being) integral with the one of said fourth idlers (28) nearest to the output of said belt, and said seventh idler (20) being mounted on said displaceable plate at said location away from the input of said stacking position and near the side of said displaceable plate opposite to that facing said first conveyor.

9. Device according to claim 8, wherein said seventh idler (20) is integral with an eighth idler (21) provided with peripheral elastic inserts (23).

l0. Stacking device according to claim 6, wherein said urging means further includes a guide member (11) which is mounted on said displaceable late (9) and which guides the displacement of said second conveyor at least during the portion of its displacement where the force exerted by said elastic member (33) on said first conveyor means is smaller than the force urging said second conveyor means towards said first conveyor means.

11. Device according to claim 1, wherein said displaceable plate (9) has a guide plate (l2, 13) for said articles, said plate having a first portion (12) facing the incoming articles which makes an angle of about 45 with said first conveyor (2) and a second portion (13) which is substantially parallel to said first conveyor.

12. Device according to claim 11, including a seventh idler (20) mounted on said displaceable plate substantially at the junction of said first (12) and second (13) portions of said guide plates.

13. Device according'to claim 12, including a second idler (15) mounted on said displaceable plate (9) near the end of said first portion (12) of said guide plate (12, 13) adjacent the input of said stacking position (7).

14. Stacking device for stacking articles diverted from a first conveyor in a predetermined position into a parallel stacking position comprising:

a second conveyor (57) mounted between said predetermined position and the input of said stacking position, said second conveyor being pivoted about its input end near said predetermined position and including a first conveyor means (31) and a second conveyor means (52, 4649, 18, 15), and said second conveyor (57) is angularly displaced as a function of the varying thickness of a stack of articles (6) accumulated in said stacking position;

means (55, 39, 19, 33) coupled to continuously urge said first and second means into contact with each other;

said urging means including an elastic member (33) one end of which is connected to the output end (32) of said first conveyor means and the other end of which is connected to a displaceable plate (9) mounted in said stacking position and displaceable as a function of the thickness of said stack; and

said other end of said elastic member is connected to said displaceable plate at a location away from the input of said stacking position and near the side of said displaceable plate opposite to that facing said first conveyor (2), whereby said first and second means cooperate to form a variable effective path length for passage of said articles. 

1. Stacking device for stacking articles diverted from a first conveyor (2) in a predetermined location into a parallel stacking position (7) comprising: a second conveyor (57) mounted between said predetermined location and the input of said stacking position, said second conveyor being pivoted about its input and near said predetermined location, and said second conveyor is angularly displaced as function of the varying thickness of a stack of articles (6) accumulated in said stacking position, such that the effective path length of said second conveyor is varied as a function of the angle it makes with said first conveyor (2); a displaceable plate (9) mounted in said stacking position and displaceable as a function of the thickness of said stack; said second conveyor includes a first conveyor means (31) the angular displacement of which is controlled by said displaceable plate, and a second conveyor means (52, 46-49, 18, 15) cooperating with said first means to form the variable effective path length of said second conveyor; and means (55, 39, 19, 33) to urge said first and second conveyor means into contact with each other, whereby said articles are conveyed between said first and second means forming the variable effective path length.
 2. Device according to claim 1, wherein said second conveyor means comprises a constant portion (52, 46-49), and a variable portion (18, 15) including a first idler (18) which is mounted on a first lever (16) pivoted on said displaceable plate (9) near the impact of said stacking position (7), the position of said first idler is controlled by said constant portion so that said first idler makes contact with said first conveyor means depending on the angular position of said constant portion.
 3. Device according to claim 2, wherein said variable portion further includes a second idler (15) mounted on the pivot axle (14) of said first lever (16) and forms, together with the adjacent portion of said first conveyor means, the input of said stacking position.
 4. Device according to claim 3 wherein said first lever (16) comprises a first cam-shaped member, the position of which is controlled by a third idler (51) mounted on said constant portion near the output end thereof.
 5. Device according to claim 4, wherein said first conveyor means (31) comprises an endless belt arranged on fourth idlers (26-38), and said constant portion of said second conveyor means comprises a plurality of juxtaposed fifth idlers (46-49) mounted on a second lever (37) which is pivoted (38) near said predetermined location.
 6. Stacking device according to claim 1, wherein said urging means includes an elastic member (33) one end of which is connected to the output end (32) of said second conveyor means (31) and the other end of which is connected to said displaceable plate (9).
 7. Stacking device according to claim 6 wherein said other end of said elastic member is connected to said displaceable plate at a location away from the input of said stacking position and near the side of said displaceable plate opposite to that facing said first conveyor (2).
 8. Stacking device according to claim 7, wherein said elastic member (33) comprises an elastic belt which is arranged around a sixth (32) and a seventh (20) idler, said sixth idler (32 being) integral with the one of said fourth idlers (28) nearest to the output of said belt, and said seventh idler (20) being mounted on said displaceable plate at said location away from the input of said stacking position and near the side of said displaceable plate opposite to that facing said first conveyor.
 9. Device according to claim 8, wherein said seventh idler (20) is integral with an eighth idler (21) provided with peripheral elastic inserts (23).
 10. Stacking device according to claim 6, wherein said urging means further includes a guide member (11) which is mounted on said displaceable late (9) and which guides the displacement of said second conveyor at least during the portion of its displacement where the force exerted by said elastic member (33) on said first conveyor means is smaller than the force urging said second conveyor means towards said first conveyor means.
 11. Device according to claim 1, wherein said displaceable plate (9) has a guide plate (12, 13) for said articles, said plate having a first portion (12) facing the incoming articles which makes an angle of about 45* with said first conveyor (2) and a second portion (13) which is substantially parallel to said first conveyor.
 12. Device according to claim 11, including a seventh idler (20) mounted on said displaceable plate substantially at the junction of said first (12) and second (13) portions of said guide plates.
 13. Device according to claim 12, including a second idler (15) mounted on said displaceable plate (9) near the end of said first portion (12) of said guide plate (12, 13) adjacent the input of said stacking position (7).
 14. Stacking device for stacking articles diverted from a first conveyor in a predetermined position into a parallel stacking position comprising: a second conveyor (57) mounted between said predetermined position and the input of said stacking position, said second conveyor being pivoted about its input end near said predetermined position and including a first conveyor means (31) and a second conveyor means (52, 46-49, 18, 15), and said second conveyor (57) is angularly displaced as a function of the varying thickness of a stack of articles (6) accumulated in said stacking position; means (55, 39, 19, 33) coupled to continuously urge said first and second means into contact with each other; said urging means including an elastic member (33) one end of which is connected to the output end (32) of said first conveyor means and the other end of which is connected to a displaceable plate (9) mounted in said stacking position and displaceable as a function of the thickness of said stack; and said other end of said elastic member is connected to said displaceable plate at a location away from the input of said stacking position and near the side of said displaceable plate opposite to that facing said first conveyor (2), whereby said first and second means cooperate to form a variable effective path length for passage of said articles. 